Question: What is the occupational carcinogen with the fastest speed of sound?
Paraphrase: The fastest speed of sound belongs to which occupational carcinogen?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q21074597 . ?ent wdt:P2075 ?obj } ORDER BY DESC(?obj)LIMIT 5 
Answer: benzene, chloroform, carbon tetrachloride